This quote suggests that an individual’s success or failure in life is not solely determined by external circumstances, or "fortune," but also significantly influenced by their personal attitudes, behaviors, and mindset. Essentially, it’s the idea that we are not just passive recipients of what life throws at us, but active participants who can shape our own destiny through our actions and reactions.

On one hand, "fortune" represents all the external factors that we can’t control, such as the socio-economic context we’re born into, the opportunities we’re given, or the random events that happen to us. These factors can indeed have a significant impact on our lives, either positively or negatively.

However, this quote suggests that our "dispositions," or our personal qualities and attitudes, are equally important. This includes our resilience in the face of adversity, our ability to seize opportunities when they arise, our willingness to work hard and persevere, our ability to learn from our mistakes, and so on. Even in difficult circumstances, a person with a positive and proactive disposition can often find ways to improve their situation or at least mitigate the negative impact.

Applying this idea to the modern world, we could say that while it’s important to acknowledge and address structural issues that create inequality and limit opportunities for certain groups of people, it’s also crucial for individuals to cultivate positive dispositions that will allow them to make the most of the opportunities they do have. In personal development, this might involve working on skills like resilience, adaptability, emotional intelligence, and self-discipline.

Furthermore, this quote may also resonate with the concept of ‘locus of control’ in psychology. People with an internal locus of control believe that they can influence their life outcomes through their own actions, while those with an external locus of control believe that their lives are determined by external forces. Research has shown that having an internal locus of control is typically associated with better mental health, higher levels of motivation, and greater success in life.

Therefore, while we can’t control all the external factors that shape our lives, we can control our own dispositions and responses. By developing a positive mindset and proactive behaviors, we can often influence our life outcomes in a favorable direction, regardless of the hand that fortune has dealt us.